JP2006528799A - Method for digital data transmission from sensor to control equipment - Google Patents

Abstract

  A method for digital data transmission from the sensor (PPS) to the control device (SG) is proposed, and the sensor value of the sensor (PPS) is divided at different resolutions for data transmission. The sensor values form a first value range with successive sensor values. The division of the first range for data transmission is performed depending on parameters important for the control device (SG).

Description

  The invention relates to a method for digital data transmission from a sensor to a control device according to the superordinate concept of the independent claim.

  A method for digital data transmission from a sensor to a control device is already known from DE 10229945 A1. In this case, the pressure sensor signal is decomposed into the same component and the differential pressure component, and the same component is transmitted from the sensor to the control device with a lower resolution than the differential pressure component.

Advantages of the present invention The method of the present invention for digital data transmission from a sensor having the structure described in the characterizing part of the independent claim to a control device is formed by a sensor value having a continuous linear range relative to the prior art. Depending on the parameters that are important for the control device, further value ranges are cut out from this range, and this further range has the advantage that it is transmitted from the sensor to the control device with a relatively large resolution. That is, these two divided value ranges are partial regions of the entire value range. These two value ranges are especially continuous with one another. This makes it possible to select a range of values that the control device advantageously requires in its evaluation, depending on parameters that are important to the control device. This saves bank width because only important values are transmitted with high resolution, yet allows high resolution at these important values.

  By means and embodiments of the dependent claims, advantageous improved embodiments of the method for digital data transmission from the sensor to the control device according to the independent claims are possible.

  Particularly advantageously, the parameter that is dependent on the selection of the range is transmitted with high resolution from the sensor to the control device, which parameter provides a range in which an algorithmic threshold for the occupant restraint means exists. This value range is already set in advance, and this value range is determined by simulation. Values below or above this are transmitted with less resolution. This is because a very clear determination regarding the trigger can be made here. These values, which are very close to the normal threshold, are important in order to make an accurate trigger decision in this case. If bidirectional transmission between the control device and the sensor is provided, the control device can transmit such parameters to the sensor. However, there is usually a unidirectional transmission from the sensor to the control equipment, and this sensor, which can be an externally installed pressure sensor, acceleration sensor, weight sensor or pre-crash sensor, is additionally controlled via a track. Energized by the instrument, the sensor adds its data to this energy supply, for example by current modulation.

  Advantageously, the range of values transmitted with a relatively high resolution is provided in the lower half of the entire range of sensor values. A very high sensor value gives a clear decision in the trigger algorithm of the control device, while a relatively low value is necessary to make a proper and accurate decision for triggering an occupant restraint such as an airbag or belt tensioner. Requires more specific inspection.

  Advantageously, the method according to the invention can also be used for driving dynamic control (Fahrdynamikregelung) and thus for example for rollover identification and ESP.

Drawings Examples of the invention are illustrated in the drawings and are explained in more detail in the following description.

FIG. 1 shows data transmission between a sensor and a control device,
Figure 2 shows the range division,
FIG. 3 shows a flowchart of the method of the present invention.

DESCRIPTION The crash sensor has a characteristic curve that is linear or otherwise shaped to detect a crash signal. The crash sensor installed outside encodes these data and transmits them to the airbag control device. In this case, the measurement area is linearly mapped to individual digital transmission values.

  The measurement area is distributed linearly into the individual permissible transmission values, resulting in a fixed and constant resolution over the entire measurement area. However, this is disadvantageous. This is because a specific range with higher resolution than the other ranges should exist for evaluation. In a pressure sensor, for example, the region where the separation between trigger and non-trigger takes place is far more important than the pressure course that is clearly above the trigger threshold. Such a trigger threshold can be fixed or adaptively changed. That is, these trigger thresholds are adaptively changed depending on the value characterizing the crash. This change is held for a predetermined time in this case, so that it is then changed again depending on the case, depending on the Crashmerkmale. It is often impossible to transmit the entire range with relatively high resolution for cost reasons.

  The range of the sensor is divided into different areas, in which the values are also distributed linearly to the existing trigger values. Naturally, for example in the case of a pressure sensor, the measurement area is divided, for example, into two identical halves. The first half with the relatively low pressure signal is now distributed in 3/4 of the possible transmission values, while the second half with the relatively high pressure value is in the remaining 1/4 of the possible transmission values. Distributed linearly. This allows a relatively low pressure value to obtain a relatively high resolution while a high pressure value is transmitted with a relatively low resolution.

  The division of values in the region is done differently and adaptively depending on the sensor and on demand for accuracy in a given interval. This division can be realized by the interface, ie the transmitter module of the sensor. In this case, for example, in the case of pressure values, the bit width of the data transmission is reduced from at least 16 bits to 8 bits, which enables significant cost savings and data reduction.

  Further application examples for this method are for example up-front sensors, peripheral acceleration sensors and acceleration sensors in control equipment. Due to the relatively high resolution of the signals of the upfront sensors at relatively low accelerations, they can also be used for pedestrian protection, for example for plausibility by other sensors, for example contact sensors. The under-tracking (LKW-Unterfahrt) can also be detected relatively well.

  In the case of peripheral acceleration sensors and sensors in control equipment, validity and crash initiation can be detected more accurately with improved resolution in small signals. These sensors are also used in this case for the determination of driving dynamic parameters and are therefore used for rollover sensing and ESP. This also facilitates the detection of the mounting direction (Einbaurichtung) for the inspection of the detaching direction (Verbaurichtung). Since the pre-crash sensor device generates a very high mass data flow (Datenflut), the method of the invention is also advantageous in this case.

  FIG. 1 shows the transmission from the sensor to the control device in a block diagram. As a sensor, a pressure sensor PPS is shown in this case, which has a sensor element 10 with a post-connected electronic device and a transmitter module 11 for transmitting sensor values. The sensor element transmits the sensor value to the transmitter module 11. This transmitter module 11 performs the division of the sensor values in the manner of the present invention depending on the parameters important to the control device. In this case, for example, a value range in which a threshold for evaluating the pressure signal exists is transmitted with a relatively high resolution. More rough divisions are possible, for example only the lower half of the pressure sensor value is transmitted with a relatively high resolution. The transmitted sensor value is then received by the receiver module 12 of the control device SG. In this case, the resolution of the sensor values is canceled, i.e. the mapping of the decomposed sensor values to the original sensor values is performed again, and these original sensor values are then evaluated in the processor 13 of the control device SG. In this case, an evaluation is performed in the trigger algorithm in order to control the connected occupant restraint means not shown here during the trigger case.

  Alternatively, instead of the pressure sensor PPS, a side or vehicle front peripheral acceleration sensor or a sensor in the control device itself can also be used by the method of the present invention. Instead of the control device for the occupant restraint means as shown here, a control device for dynamic running control is also possible. Kinematic sensor platforms can also use the method of the present invention for transmission of their sensor values.

  FIG. 2 illustrates and illustrates the division of sensor values into transmission values. The sensor element 10 generates sensor values from 0 to 200, which are illustrated in the first part 20. However, the threshold value in the control device SG exists in the region 22, and this region 22 is from 0 to 50. That is, another region 23 from 50 to 200 is not very important. Because this region provides a clear trigger, these values are well above the threshold. Therefore, the area 22 is transmitted with a relatively high resolution. This is done by mapping to possible transmission values 21. In this case, the transmission value 21 is 8 bits from 0 to 255. In the first region 24 of transmission values from 0 to 180, the values of region 22 are linearly mapped and are therefore transmitted with a relatively high resolution. The region 23 is mapped to the range 25 and is therefore transmitted to the control device SG with a relatively low resolution. A corresponding resolution can be signaled from the sensor PPS to the control device SG in the data telegram.

  FIG. 3 illustrates the course of the method of the present invention in a flowchart. In method step 300, a sensor value is generated by the sensor element 10 and is amplified, digitized and filtered in the electronic device to which it belongs. The sensor values thus digitized are then supplied to the transmitter module 11, which divides the sensor values according to the invention in method step 301. The transmitter module 301 performs the segmentation of sensor values depending on parameters important to the control device, in this case depending on possible thresholds for the trigger algorithm. The transmitter module selects the range where these thresholds may exist to transmit with a relatively high resolution, while the transmitter module transmits the range outside it with a relatively low resolution. In method step 302, the sensor values thus divided are then transmitted. In method step 303, these sensor values are received by the control device SG using the receiver module 12 and supplied to the processor 13 for processing in the trigger algorithm.

  As an example, the sensor value 48 of FIG. 2 is generated. This exists in region 22. This measured value 48 is therefore transmitted with a relatively high resolution in the region 24. In this case, transmission values 168 to 171 are used for this measured value 48 as an example.

Fig. 4 illustrates data transmission between a sensor and a control device. Indicates range division. 2 shows a flowchart of the method of the present invention.

Explanation of symbols

PPS pressure sensor SG control device 10 sensor element 11 transmitter module 12 receiver module 13 processor 20 first part 21 possible transmission value 22 region 23 region 24 range

Claims (5)

A method for digital data transmission from a sensor (PPS) to a control device (SG) comprising:
In the method for digital data transmission from the sensor (PPS) to the control device (SG), the sensor value (20) of the sensor (PPS) is divided at different resolutions (24, 25) for data transmission.
The sensor values form a first range (22, 23) having successive sensor values, and the division of the first range (22, 23) for data transmission is an important parameter for the control device (SG). Method for digital data transmission from a sensor (PPS) to a control device (SG), characterized in that   The parameter is the second range (22) of the threshold value of the trigger algorithm of the occupant restraint means, and the sensor value (22) in the second range is from the sensor (PPS) to the control device (SG) with a relatively high resolution (24). 2. The method of claim 1, wherein   Method according to claim 2, characterized in that the second range (22) is selected from the lower half of the first range.   Use of a transmitter module (11) in a sensor (PPS) for carrying out the method according to one of claims 1-3.   Use of a receiver module (12) in a control device (SG) for performing the method according to one of claims 1-3.

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